Production of light



F. H. BAlLEY Feb. 19 1924.

InUenZbr Feb. 19, 1924. 1,484,287 v F. H. BAlLEY PRODUCTION OF LIGHT Filed y 17. 1921 2 Sheets-Sheet 2 Patented Feb. 19, 1924.

UNITED "STATES PATENT oFnCfiE;

. .R g V FRANK BAILEY, OF CINGINNATI, OEIO.

PRODUCTION OF LIGHT;

. Application filed Kay 17, 1921. Serial No.470,489.

To all whom it may concem:

Be it known that I, FRANK H. BAILEY, a

citizen of the United States, and a residentof Cincinnati, in the county of Hamilton* and State of Ohio, have invented certain new and useful Improvements in the Production of Light, of which the following is a full, clear, and exact description, reference being had to the accompanying drawin forming part ofthis specificatlon.

y inventlon relates to the roduction of' transparent media for the Conversion ;of artificial light to give as close an approximati'on as possible to the so-called natural day-light, produced by the sun as'reacted upon by the atmosphere of the earth.

As is well known, the air acts upon the 'whitelight emanating from the sun in such a way as to difluse and to a certain extent color it. Thus the natural color of the clear sky is a good indication of the eflect of the atmosphere on the light of the sun so far as color tendenc is concerned.

-The artificial ight from a. burning hydrocarbon is very poor in the Violet and bluesince the are the common Ones practical forinterior lllumination, for example, the electric arc and incandescent Vapor lights are troublesome to take care of and require expensive apparatus. In my Invention I take as the source of light, theincandescent filament, although a gas or oil flame should be included. The light from such a filament has a predomnant yellow color, as well as bein weak in blue and Violet rays, so that my invention has as its 'object the suppression of the yellow color and 'the increasing ef -the blue and-Violet. i

I accomplish my invention by that certain construction and arrangement of parts to be hereinafter more specifically pointed out and claimed, whereby, among other things,- I so treat the light emanating from an' artificial source as to give it 'a nature, which upon Spectrum analysis' will be found to approach the, Spectrum of day-light or atmosphere-refracted sunli'ght In the drawings,

Figure 1 is a erspective view of a plato of glass constructed according to my invention, *same being magnified over its natural size. 7 l Fi ure 2 is a diagrammatc view illustrating t ie action of my special glass structure -on raysof light from an'incandescent fila ment.

Fi re 3 is a view of a s ial electric lightbulb illustrating one ap ication of my y invention. 4

Figure 4 is an elevation of a Vehicle lamp 'illustrating another application of my invention. y

Figure 5 is an elevation of an ordinary light bulb witha hood or cover embodying my invention Figure.6 is an illustration of a dome light with' a shade embodying my invention.

F igure 7 is a Perspective of a hanging light 'witl 'a shade embodying my invention. Figure 8 is a erspective 'of a desk lamp showing the use of a cover plate thereon,

which embodies my invention.

As was stated above, it is myobject to imitate in; an artificial light the same illuminating 'properties of ordinary daylight, thus providing, amon for a 'true' revealin of de icate shadings and colors by artificlal light.- In art avork, display of paintings, display of cloth, this simulation of day-light has special value.

v Also in view of the fact that the eye' is saved the necessity of adjusting itself from the white'light of da to the yellowish light of lamps, the use o my invention for all interior and exterior lighting purposes is valuable The casting of a single colorover all Objects viewed as is done by yellow artificial light, forces the eye to use apart ,only of its forces, thus tiring it and reducing the efficiency of any one working under it.

The use as a searchlight or Vehicle light of a ra which throws a substantially pure day-lig it'hue over objects within its beam not only gives a clear illumination but makes it easier to distinguish the exact naother things,

There are two features' to my invention, both of which Combine to give a white light from a source fairly rich in yellows and reds and which serve to re-act on artificial light as the atmosphere does on light emanating from the sun.

These two things are,--(1) the provision of a transparent medium for the passage of the li 'ht which has a color as close to the blue s as Ossible, i. e., of a color which is termed a lig t ultramarine blue Or cerulean blue, and (2) the engravingor Otherwise lol-ming on the surface of this lass of'a number of very fine grooves, w ich act by mutal reflection from the oove walls and prismatic action, due to t e un-- even thickness of the surface, to cut down the red and yellow components of the light.

In describing the theory upon which I believe my invention to be-based, I do not desire to thereby limit my invention, which I desire to stand upon its structural details and the results produced thereby rather than upon the correctness of the theory, I may sa however, that the invention was ori ina ly based upon empirical reasoning rat er than experimentation.

I take a piece of sky blue glass, such as the piece A (Figure 1) and engrave it with a Series of parallel Or roughly parallel lines, which should act to form a series' of very fine prisms On the surface of the glass. Thus as indicated in Figure 1, if a glass B should be used, the grooves C should be in the form of prisms abutting each Other across the surface of the glass.

In order to avoid confusion as' to scale, I have noted on Figure 1 the depth of the grooves as being one hundredth of an inch and the space between crests left between the grooves as fifteen-thousandths of an inch.

Referring to Figure 2, I have shown very greatly enlarged, a pair of the prism-like structures formed on the glassA and a source of light S. The lines drawn are intended to indicate the path of a pencil of light into the prisms where it will be noted that the light is deflected with the Violet ra V receivin more deflection than the re ray R, an thus the Violet ray, upon the reflection from the inside and outside of does not obscure it.

Ordinary frosting of a piece of glass does not serve my purpose at all, nor would a series of criss-cross' lines, so far as I am advised. In my experimenta I have deter- 'prising a body of bluish color wi mined that the best A results are obtained where the lines bear the nearest parallelism to each other and are regularly cut or engraved, so as to give a magnified appearance, such as I have shown in Fi re 1. V

Due to the fact that I find no difl'erence if the transparent medium is flat or curved, I gain advantage of my invention in many ways. Thus in Figure 3 I may use the special glass X of sky blue with parallel, closely adjacent scorings or grooves therein, in the form of a bulb 1.

In Figure 4 the special glass is shown as makin up the door 2 of a Vehicle lamp 3.

In igure 5, the special glass is shown as formed into a transparent housing 5 for an ordinary electric globe 6.

In Figure 6 is shown a dome-shaped globe 7 placed Over a cluster of ceiling lights 8. In Figure 7 is a hanging lamp having electric bulbs 9 and-a globe 10 of the special lass, and in Figure 8 is shown a desk lam avin a standard 11, on which is supporte a sha e 12 that houses a bulb 13. Over the face of the reflector I have placed a sheet of my special glass as at 14.

As heretofore stated, the reasons for my success in etting an artificial light approaching t at of daylight are not stated as limitations thereof, but the structure and composition of the 'special glass and the results of use thereof I wish to clearly state.

Thus I have found that artists workinlg on living models especially find it impossib e to get correct shadmgs by any form of colored glass heretofore known to them, including exactly the same cerulean blue which I employ as above noted, with bulbs of cerulean blue engraved with the lines, as by any desired form of ruling engine, artists have for some time been painting at night in life claes with perfect success.

Because of the ex rience of artists who are speciall skilled in the determination of delicate s adings of color, I am convinced that by my invention I have so treated the rays of li ht coming from an incandescent filament tfiat they are of precisely the same color-revealing pro rty as slmligllllt acted upon by the atmosp ere of the eart Havmg thus deecribedmy invention, what I claim as new and desireto secure by Letters Patent, is:-- i 1. A glass for tr'ansmission of li ht, coma series of fine markmgs substantially parallel to each Other engraved in the surface thereof, for the purpose described.

2. A glass for transmission of light, com- Eising a-body of blush color, said body ing engraved in its surface with a series of angular grooves substantially parallel to each other, so as to impart a prismatic nature to said surface.

3r A glass for transmiaeion of light, comllO prising a body of bluish color, said body being engraved in its surface With a, series of closely adjacent tapered grooves lying substantially parallel to each Other and hav- 6 ing a triangular ridge between them, so a's to impart a prismatic efl'e ct to the glass. 4. A glass for transmission of light, comprising a body of bluish color, said body being engraved in its surface with a series of closely adjacent tapered grooves lying substantially parallel to each Other and having a triangular ridge between them, so as to impart a prismatic efl'ect to the glass, said grooves having a depth of substantially one hundredth of an inch Or less.

FRANK H. BAILEY. 

